1. Field of the Invention
The present invention generally relates to a motor control apparatus for driving an electric motor on the basis of motor current values and current command values. More particularly, the present invention is concerned with a motor control apparatus which is imparted with an overheat protection function for a polyphase motor such as a DC brushless motor or the like (hereinafter simply referred to as the motor).
2. Description of Related Art
As the conventional motor control apparatus known heretofore, there has been proposed a control apparatus equipped with a temperature protecting means for the motor. By way of example, reference may have to be made to e.g. Japanese Patent Application Laid-Open Publication No. 238293/2002 (JP-A-2002-238293).
In the conventional motor control apparatus, it is necessary to execute an integration arithmetic operation on the basis of a predetermined function for each of phase currents. Consequently, overhead involved in the arithmetic processing increases remarkably, imposing an excessively large processing load on a microcomputer or microprocessor, giving rise to a problem.